Mr. Ueno, a retiree living alone, communicates with Maria, a maid-android whom his parents bought several decades ago. Maria became Ueno's companion after his parents' death, but now her battery is running down and there are no spare parts. Against the backdrop of conversations and the sensual memories of Maria and Ueno, Inspector Akagi searches for a serial rapist, suspecting that the rapes are being committed by... a robot.